Cinematographic apparatus.



J. LEHMANN.

CINEMATOGRAPHIC APPARATUS.

APPLICATION FILED APR. 24. 1913.

1,214,798. Patented Feb. 6,1917.

UNITED STATES PATENT OFFICE.

J OHANNES LEHMANN, 0F JENA, GERMANY, ASSIGNOR TO THE FIRM Oil? CARLZEISS,

OF JENA, GERMANY.

CINEMATOGRAPHIC APPARATUS.-

Specification of Letters latent.

Patented Feb. 6, 1917.

Application filed 1pri1 24, 1913. Serial N 0. 763,449.

'means of any number of simultaneously operative. objectives, each ofwhich is tem porarily screened, c. 9., in the case of a filmband withintermittent motion, for the duration of the change from one picture toanother. The screening is effected in the well-known apparatus as a ruleby means of a rotatable screening disk, which is rotatedcorresponding'to the motion of the film- 'bandand is disposed either inthe objectives or in their vicinity. According to the present inventionthe movable screen is not fitted in the said manner, but at a suitableplace in the path of the rays of the lighting pencil between the sourceof light and the film-band and an image is formed of it by means of anoptical system, which at the same time belongs to the lighting system ofthe apparatus, in the objectives. A art from the constructive advantage,that it is then no longer obligatory to fit the screen in the vicinityof the objectives, iii-which position it is often inconvenient, itbecomes possible through the new arrangement in the case where an imageis formed in the objective, to. cause the obscuring to take placesimultaneously over the entire surface of the picture, Without having tomount the screen, as is necessary in the constructions known up to thepresent, between the lenses of the objective. It will be foundconvenient, for bringing about a uniform obscuration of theentire-surface of the picture, to dispose-the screen at a place, wherethere is an image of the source of light. An additional advantage of thenew disposition lies in the fact, that the. screen in its effectivepositions keeps-the light and thereby the heating efl'ects'of the samefrom the film.

tives, which simultaneously receive ray-penoils from the'same source oflight, an arrangement frequently made use of, when coloredcinematographic pictures are being presented, a further advantageresults from the adoption of the invention. In

-When the apparatus has several objec-' such a case two or more picturesare simultaneously projected on a screen, so that the obscuration, e.9., for the change from one p cture to another, shall take place notonly w thin each separate picture, but alsoconointly for the said two.or more pictures in a uniform manner. This can be brought about by thescreen being fitted at a locus, 1n which an undivided image of thesource of light is formed, so that the screen obscures simultaneouslyall the pictures lighted by the same source of light.

In the annexed drawing there is diagrammatically shown, as an example ofhowthe lnvention may be realized, a cinematographic apparatus with threeobjectives for presenting colored pictures, Figure 1 showing alongitudinal section of the apparatus and Fig. 2 a front view of thescreen-disk. In this example a denotes a source of light,-b b acondenser system'and c a col lective lens. The condenser system b 6forms in close proximity to the lens 0 and on that side of it, which isremote from the said condenser system, an image of the source of' lighta, of which at the same time an image is formed by auxiliary condenserlenses marked at, d and d" respectively-in the diaphragm-plane of'eachof the three projection-objectives marked respectively 6, e and e". Inthe vicinit of the condenser system 6 b is situate a rotatablecolorfilter disk f, the function of which is to provide each picturewith its requisite color and of which an image is formed by means of thecollective lens 0 on the plane w wof the film-band, whileadjacentto thecollective lens a, at the'locus of the image formed by b, b of thesource of light, therotatable screen-disk g is fitted, which is fixedalong with the color-filter disk on a-common arbor and is rotated,corresponding to. the motion of the film-band, by means of a positivemotion-transmission indicated in the drawing by the toothed wheel it. By-means of i In order that affected by the lens 0, as this latter lenslies in close proximity of the .plane of the said image; likewise theimage of the colorfilter disk f formed by the lens 0 is practically notaffected by the lenses 0? and d. in spite of the distance apart of theaxes of the three objectives the'pictures belonging to each of theobjectives may be lighted by ray-pencil systems having parallel axes,the retracting prisms k and is are fitted in front of. the auxiliarycondenser lenses (Z and d.

I claim:

1. In a cinematographic apparatus 5 a source of light, a condenser nearthe source of light, a film adapted to travel through the path of therays coming from the source of light, opticalmeans adapted to form animage of the said film, a screen movably disposed between the source oflight and the said optical means in the path of the said rays and otheroptical means adapted to form an image of the said screen in the locusof the first named optical means.

2. In a cinematographic apparatus a plurality of objectives, a sourceof'light, a condenser near the source of light, a film adapted to travelthrough the path of the rays coming from the source of light, a screenmovably disposed in the path of the said rays at a locus,

form an image of the said screen in the locus of the said objectives.

3. In a cinematographic apparatus a plurality ot'objectives, a source oflight, a condenser ,near the source of light, a filmadapted to travelthrough the path of the rays coming from the source of light, a screenmovably disposed in the path of the said rays at a locus, in 'Whichthere is an undivided image of the source of light, formed by the saidcondenser, and optical means adapted to form an image of the said screenin the locus of the said objectives.

J OHANNES LEHMANN.

Witnesses:

PAUL KRUGER, FRITZ SIANDER.

in Which there is an image ,of the source of light, formed by the saidcondenser, and optical means adapted to

